JP2007308753A - Heat resistant diamond-like thin film, machine part provided therewith, die, and its production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a DLC film having excellent heat resistance and wear resistance. <P>SOLUTION: The heat resistant diamond-like thin film is deposited on the surface of a base material and comprises silicon. The concentration of the silicon in the grain boundary with the base material is higher than the concentration of the silicon in the surface, and the change in the concentration of the silicon between the grain boundary with the base material and that in the surface is continuous. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a heat-resistant diamond-like thin film, a machine part including the same, a mold, and a method for manufacturing the same, and in particular, a machine part and a metal used under conditions that are at least intermittently exposed to 300 ° C. The present invention relates to a mold and a manufacturing method thereof.

  A diamond-like thin film (DLC film) called diamond-like carbon is a hard thin film material and has an amorphous structure and is excellent in surface roughness.

  For this reason, it has been actively used in recent years to improve the durability of mechanical parts that involve sliding. In particular, it is applied to an internal combustion engine for automobiles, which is an assembly of advanced machine parts (see, for example, Patent Documents 1 and 2).

  Further, in high-precision glass molding such as optical glass, a high-precision glass molding die having excellent shape accuracy and surface roughness is required. In a mold for molding, it is difficult to maintain surface accuracy because the mold surface is oxidized by heating. In order to maintain surface accuracy, it has been attempted to coat the mold surface with a thin film having a basic composition of a noble metal such as platinum. However, since noble metal materials have low hardness, surface accuracy deteriorates due to wear during continuous use.

By using a thin film in which oxides such as zircon oxide (ZrO ₂ ), titanium oxide (TiO ₂ ) and tantalum oxide (Ta ₂ O ₃ ) are dispersed in a noble metal as a method for preventing deterioration of surface accuracy due to wear. A method for compensating the hardness of the noble metal material has been proposed (see, for example, Patent Document 3). Further, a glass molding die using a thin film in which boron compounds such as titanium boride (TiB ₂ ) and zircon boride (ZrB ₂ ) are dispersed in a noble metal has been proposed (see, for example, Patent Document 4). .)
JP 2005-36666 A JP 2006-22666 A Japanese Examined Patent Publication No. 2-49256 Japanese Examined Patent Publication No. 4-2607

  However, the mechanical equipment covered with the DLC film has a problem that the heat resistance is insufficient. The DLC film has a problem in use at high temperatures because the amorphous structure shifts to a graphite-like structure as the temperature is raised. In general, the heat-resistant temperature of the DLC thin film is about 300 ° C. to 400 ° C., and in order to apply the DLC film to a location exceeding 400 ° C. such as the inside of the engine, it is necessary to prevent deterioration of the DLC film due to heat.

  On the other hand, a material having smoothness, wear resistance and heat resistance is desired for the thin film used for maintaining the surface accuracy of the mold. Since the DLC film has smoothness and wear resistance, it is expected as a thin film used for maintaining the surface accuracy of the mold, but there is a problem that the heat resistance is insufficient as described above.

  The present invention solves the above-mentioned conventional problems, and is characterized in that a DLC film excellent in heat resistance and wear resistance, and a machine part and a mold including the DLC film can be realized.

  In order to achieve the above object, the present invention has a diamond-like thin film in which the silicon concentration at the interface with the substrate is higher than the silicon concentration at the surface and the silicon concentration continuously changes.

  Specifically, the heat-resistant diamond-like thin film according to the present invention is formed so as to cover the surface of the base material, contains silicon, and the silicon concentration at the interface with the base material is higher than the silicon concentration at the surface. The silicon concentration is continuously changed between the interface with the material and the surface.

  According to the heat-resistant diamond-like thin film of the present invention, since the silicon concentration at the interface with the substrate is higher than the silicon concentration at the surface, the thermal conductivity of the diamond-like thin film is lowered and the surface heat is reduced from the substrate. It becomes difficult to be transmitted to the interface side. Therefore, since heat cracks and peeling from the substrate are less likely to occur, the heat resistance of the diamond-like thin film is improved. Moreover, since the hardness on the surface can be sufficient, both wear resistance and heat resistance can be achieved. Furthermore, since the change in the silicon concentration between the interface with the substrate and the surface is continuous, peeling at the discontinuous interface does not occur.

  The mechanical component according to the present invention includes a base material and a diamond-like thin film that covers the base material and contains silicon, and the diamond-like thin film has a lower concentration of silicon on the surface than the interface with the base material. The silicon concentration is continuously changing.

  According to the mechanical component of the present invention, since the diamond-like thin film containing silicon is provided, the concentration of silicon on the surface is lower than the interface with the base material, and the concentration of silicon is continuously changed. The diamond-like thin film covering the surface of the component is less likely to cause heat cracks and the like, and the surface wear resistance can be secured. Therefore, it is possible to easily realize a machine part having both heat resistance, wear resistance and smoothness.

  In the mechanical component of the present invention, the diamond-like thin film preferably has an atomic percentage concentration of silicon of 50% or less in a portion where the silicon concentration is highest. With such a configuration, both heat resistance and wear resistance can be reliably achieved.

  In this case, the diamond-like thin film preferably has the highest silicon concentration at the interface with the substrate.

  The diamond-like thin film preferably has a silicon concentration of 90% or less of the silicon concentration at the highest silicon concentration.

  In the mechanical component of the present invention, the diamond-like thin film preferably has a larger elastic coefficient at the surface than that at the interface with the substrate. In this case, the diamond-like thin film preferably has an elastic modulus of 50 GPa or more and 400 GPa or less on the surface thereof.

  In the mechanical part of the present invention, the diamond-like thin film has a graphite bond and a diamond bond, and the existence ratio of the graphite bond to the diamond bond on the surface of the diamond-like thin film is the presence of the graphite bond to the diamond bond at the interface with the substrate. The ratio is preferably smaller than the ratio.

  In the mechanical component of the present invention, the base material preferably has an arithmetic average surface roughness of 0.1 nm or more and 300 nm or less on the surface thereof.

  The method of manufacturing a mechanical component of the present invention includes a step (a) of preparing a base material, and a step (b) of forming a diamond-like thin film containing silicon on the surface of the base material. The thin film is characterized in that the concentration of silicon on the surface is lower than that of the interface with the substrate and the concentration of silicon is continuously changed.

  According to the method of manufacturing a mechanical component of the present invention, the diamond-like thin film is formed so that the concentration of silicon continuously changes so that the concentration of silicon is lower than the interface with the base material on the surface of the diamond-like thin film. Therefore, it is possible to easily realize a mechanical component covered with a diamond-like thin film that hardly causes heat cracks and has surface wear resistance.

  In the method for manufacturing a mechanical component of the present invention, in the step (b), the diamond-like thin film is preferably formed so that the atomic percentage concentration of silicon in the portion having the highest silicon concentration is 50% or less.

  In this case, in the step (b), the diamond-like thin film is preferably formed so that the concentration of silicon is highest at the interface with the substrate.

  In the step (b), the diamond-like thin film is preferably formed so that the silicon concentration on the surface thereof is 90% or less of the silicon concentration in the portion where the silicon concentration is highest.

  In the method for producing a mechanical component of the present invention, in the step (b), the diamond-like thin film is preferably formed so as to have a larger elastic modulus at the interface with the elastic modulus substrate on the surface.

  In the method for manufacturing a mechanical component of the present invention, in step (b), the diamond-like thin film has a graphite bond and a diamond bond, and the ratio of the graphite bond to the diamond bond on the surface of the diamond-like thin film is the interface with the substrate. It is preferable to form it so as to be smaller than the ratio of the graphite bond to the diamond bond.

  A mold according to the present invention includes a mold body and a diamond-like thin film that covers the mold body and contains silicon, and the diamond-like thin film has a silicon concentration on the surface thereof compared to the interface with the mold body. And the concentration of silicon is continuously changing.

  According to the mold of the present invention, a diamond-like thin film containing silicon is provided, and the concentration of silicon is lower and continuously changing at the surface of the diamond-like thin film than the interface with the base material. The diamond-like thin film covering the mold surface is less likely to cause heat cracks and the like, and the surface wear resistance can be secured. Therefore, it is possible to easily realize a mold capable of ensuring surface accuracy over a long period of time.

  In the mold of the present invention, the diamond-like thin film preferably has an atomic percentage concentration of silicon of 50% or less at a portion where the silicon concentration is highest. With such a configuration, both heat resistance and wear resistance can be reliably achieved.

  In this case, the diamond-like thin film preferably has the highest silicon concentration at the interface with the mold body.

  The diamond-like thin film preferably has a silicon concentration of 90% or less of the silicon concentration at the highest silicon concentration.

  In the mold of the present invention, the diamond-like thin film preferably has a larger elastic coefficient at the surface than that at the interface with the mold body. In this case, the diamond-like thin film preferably has an elastic modulus on the surface of 50 GP or more and 400 GPa or less.

  In the mold of the present invention, the diamond-like thin film has a graphite bond and a diamond bond, and the abundance ratio of the graphite bond to the diamond bond on the surface of the diamond-like thin film is higher than the graphite bond to the diamond bond at the interface with the mold body. It is preferable that the abundance ratio is smaller.

  In the mold of the present invention, the mold body preferably has an arithmetic average surface roughness of 0.1 nm or more and 300 nm or less on the surface thereof.

  The manufacturing method of the metal mold | die which concerns on this invention is equipped with the process (a) which prepares a metal mold | die main body, and the process (b) which forms the diamond-like thin film containing a silicon | silicone on the surface of a metal mold | die main body, Process (b) The diamond-like thin film is characterized in that the concentration of silicon on the surface is lower than that of the interface with the mold body and the concentration of silicon continuously changes.

  According to the mold manufacturing method of the present invention, the diamond-like thin film is formed so as to continuously change so that the concentration of silicon is lower than the interface with the base material on the surface of the diamond-like thin film. Therefore, it is possible to easily realize a mold covered with a diamond-like thin film that hardly causes heat cracks and has surface wear resistance.

  In the method for producing a mold of the present invention, in the step (b), the diamond-like thin film is preferably formed so that the atomic percentage concentration of silicon in the portion having the highest silicon concentration is 50% or less.

  In this case, in the step (b), the diamond-like thin film is preferably formed so that the concentration of silicon is highest at the interface with the mold body.

  In the step (b), the diamond-like thin film is preferably formed so that the silicon concentration on the surface thereof is 90% or less of the silicon concentration in the portion where the silicon concentration is highest.

  In the mold manufacturing method of the present invention, in the step (b), the diamond-like thin film is preferably formed so that the elastic coefficient at the surface thereof is larger than the elastic coefficient at the interface with the mold body.

  In the mold manufacturing method of the present invention, in step (b), the diamond-like thin film has a graphite bond and a diamond bond, and the abundance ratio of the graphite bond to the diamond bond on the surface of the diamond-like thin film is different from that of the mold body. The graphite bond is preferably formed to be smaller than the abundance ratio of the graphite bond to the diamond bond at the interface.

  The heat-resistant diamond-like thin film according to the present invention and the machine part and mold including the same can realize a DLC film excellent in heat resistance and wear resistance and a machine part and mold including the DLC film.

  The heat-resistant DLC film according to the present invention is a diamond-like thin film (DLC film) containing silicon (Si) that covers the surface of a substrate such as a machine part and a mold. Further, the Si concentration at the interface between the DLC film and the substrate is higher than the Si concentration at the surface. Further, the Si concentration continuously changes between the interface with the substrate and the surface.

  The inventors of the present application have found that the heat resistance of the DLC film is improved by adding Si to the DLC film. The principle that the heat resistance of the DLC film is improved by the addition of Si is not clear at present, but the thermal conductivity of the DLC film is lowered by the addition of Si, so that the DLC film absorbs heat from the outside. It is thought that it may be difficult to do. Moreover, since the hardness of a DLC film falls by adding Si, it is thought that the effect that the stress added to a DLC film is relieve | moderated and a heat crack becomes difficult to generate | occur | produce is also acquired.

  It has been found that the heat resistance of a DLC film improves as the amount of Si added increases. However, since the wear resistance decreases as the amount of Si added increases, the amount of Si added is limited when Si is added to the entire DLC film. In addition, when a plurality of DLC films having different Si addition amounts are stacked, discontinuous surfaces with different thermal conductivities are generated, and peeling is likely to occur.

  However, in the DLC film of the present invention, the Si concentration on the interface side with the substrate is higher than the Si concentration on the surface, and the Si concentration continuously changes. For this reason, heat resistance can be improved while ensuring the wear resistance on the surface of the DLC film, and there is no fear of peeling due to discontinuous surfaces. Note that the Si concentration only needs to change continuously, and there is no problem even if the pattern once increases from the interface with the substrate and then decreases toward the surface.

  The material of the base material in the present invention is not particularly limited. For example, metals, ceramics, heat resistant plastics, and the like can be used.

  In addition, by forming the DLC film of the present invention on the surface of a mechanical part, it is possible to realize a mechanical part having a smooth surface and excellent lubricity, as well as excellent wear resistance and heat resistance. The machine parts in this case are not particularly limited, but are intermittently or continuously 300 ° C. such as engine-related machine parts such as pistons, piston rings and engine valves, welding nozzles, stranded wire guide rollers, turbine bearings, and bearings. An excellent effect is obtained when the part is used in a portion exposed to the above temperature and requires smoothness, wear resistance and heat resistance.

  Further, by forming the DLC film of the present invention on the surface of the mold, it is possible to realize a mold that has excellent surface accuracy and can maintain the surface accuracy for a long time. The mold in this case is not particularly limited, but is a cold in which the mold surface temperature is locally heated to 300 ° C. or more by a mold for molding such as glass having a molding temperature of 300 ° C. or higher, or by severe ironing. An excellent effect is obtained in the case of a die that requires heat resistance, such as a hot press die, a cold forging die, and a warm forging die having a molding temperature of 500 ° C. or higher.

  It has been found that the adhesion between the substrate and the DLC film can be further improved by keeping the surface roughness of the substrate surface within a certain range. When the surface roughness on the substrate surface is too small, the anchor effect of the thin film on the substrate surface is reduced, and the adhesion between the substrate and the DLC film is reduced. In addition, in order to reduce the surface roughness, long time electrolytic polishing is required, resulting in high cost. On the other hand, by increasing the surface roughness, the electropolishing time can be shortened and the cost can be reduced. However, when the surface roughness of the substrate surface is larger than the film thickness of the DLC film, it is uniformly formed. There is a possibility that the film cannot be formed. Therefore, the arithmetic average surface roughness (Ra) on the substrate surface may be 0.1 nm or more and 300 nm or less, and preferably 1 nm or more and 200 nm or less.

  The DLC film is formed by sputtering, DC magnetron sputtering, RF magnetron sputtering, chemical vapor deposition (CVD), plasma CVD, plasma ion implantation, superimposed RF plasma ion implantation, ion plating, arc It can be formed on the surface of the substrate by a known method such as an ion plating method, an ion beam vapor deposition method or a laser ablation method.

  When forming a DLC film, a gas that is a silicon source such as tetramethylsilane (TMS) is added, and the amount added is continuously changed, so that Si is contained and the surface side is changed from the interface side to the base material. As a result, a DLC film in which the Si concentration continuously decreases can be obtained. However, if the Si concentration is too high, the proportion of SP3 bonds decreases, and it does not function as a DLC film. For this reason, the atomic percentage concentration of Si in the portion with the highest silicon concentration is preferably 50% or less. In addition, it is preferable to increase the Si concentration at the interface with the base material because the heat resistance is improved. Furthermore, in order to ensure wear resistance on the surface, the Si concentration on the surface is made lower than the Si concentration on the interface with the substrate. Further, it is preferable to form a concentration gradient by making the Si concentration on the surface 10% or more lower than the concentration of the highest concentration portion.

  By changing the Si concentration in the DLC film, the proportion of graphite bonds (SP2 bonds) and diamond bonds (SP3 bonds) in the bonds between carbon atoms in the DLC film changes. Therefore, the ratio of the SP2 bond to the SP3 bond in the DLC film is larger than the surface at the interface with the substrate.

  Further, the elastic modulus (Young's modulus) of the DLC film also changes as the ratio of SP2 bonds and SP3 bonds changes. Since the ratio of SP3 bonds is high on the surface of the DLC film, the Young's modulus is higher than that of the interface with the substrate. The Young's modulus on the surface of the DLC film may be 50 GPa or more and 400 GPa or less, and preferably 80 GPa or more and 300 GPa or less.

  The thickness of the DLC film is desirably thin when importance is placed on accuracy such as surface roughness, but a film thickness of at least 20 nm is necessary to form a concentration gradient in the Si concentration. Thickness is more preferred. Further, when heat resistance is important, it is desirable that the film thickness is thick, but in order to suppress the influence of stress accumulated in the film, the thickness is preferably 10 μm or less, more preferably 3 μm or less.

  The DLC film can be directly formed on the surface of the base material, but an intermediate layer may be provided between the base material and the DLC film in order to more firmly adhere the base material and the DLC film. In the case of providing the intermediate layer, various materials can be used depending on the material of the substrate, but Si and carbon (C), titanium (Ti) and carbon (C), or chromium (Cr) and carbon (C A known film such as an amorphous film made of

  In addition, since the intermediate layer needs to be formed uniformly on the surface of the substrate, a certain degree of film thickness is required. However, if the film thickness is too thick, the film formation time becomes long and the productivity is lowered. Therefore, the film thickness of the intermediate layer may be 5 nm or more and 3 μm or less, preferably 10 nm or more and 1 μm or less.

  The intermediate layer can be formed using a known method. For example, a sputtering method, a CVD method, a plasma CVD method, a thermal spraying method, an ion plating method, an arc ion plating method, or the like may be used.

  Hereinafter, the heat-resistant DLC film, the machine part and the mold according to the present invention will be described in more detail with reference to examples.

(Example)
A DLC film was formed on the surface of a test piece made of cemented carbide (equivalent to K-10) having a 12 mm square and a thickness of 6 mm as a model of a machine part or a mold.

FIG. 1 schematically shows an ionization vapor deposition apparatus used in the present embodiment. A DC arc discharge plasma generator 21 provided in a vacuum chamber is connected to Ar and benzene (C ₆₎ as ion sources. This is an ordinary ionization deposition apparatus for solidifying a DLC film on the target 22 by colliding the plasma generated by introducing H ₆ ) gas with the target 22 biased to a negative voltage.

The test piece was set in a chamber of the ionization vapor deposition apparatus, after introducing to argon gas (Ar) pressure becomes ^{10 -1 Pa~10 -3 Pa (10 -3} Torr~10 -5 Torr) in the chamber Then, Ar ion was generated by discharging, and bombard cleaning was performed for about 30 minutes to cause the generated Ar ions to collide with the surface of the test piece.

Subsequently, tetramethylsilane (Si (CH ₃ ) ₄ ) was introduced into the chamber for 3 minutes to form an amorphous intermediate layer having a thickness of 10 nm mainly composed of silicon (Si) and carbon (C). The intermediate layer is provided in order to improve the adhesion between the test piece and the DLC film, and may be omitted when sufficient adhesion between the test piece and the DLC film 12 can be secured.

After forming the intermediate layer, a DLC film containing Si was formed by performing discharge while introducing a mixed gas of tetramethylsilane and C ₆ H ₆ gas into the chamber. As shown in Table 1, the mixing ratio of tetramethylsilane and C ₆ H ₆ gas was changed with the passage of film formation time.

At this time, the pressure in the chamber was adjusted to 10 ⁻¹ Pa. The substrate voltage was 1.5 kV, the substrate current was 50 mA, the filament voltage was 14 V, the filament current was 30 A, the anode voltage was 50 V, the anode current was 0.6 A, the reflector voltage was 50 V, and the reflector current was 6 mA. Moreover, the temperature of the test piece at the time of formation was about 160 ° C. Note that it is also possible to form a DLC film containing Si and fluorine by adding a gas containing fluorine such as CF ₄ when forming the DLC film.

  Below, the result of having performed various analysis about the test piece provided with the obtained DLC film containing Si is shown. As a comparative example, a test piece in which a DLC film was formed without supplying tetramethylsilane was used.

  FIG. 2 shows the result of analyzing the constituent components of the obtained DLC film. For the measurement, a PHI-660 scanning Auger electron spectrometer manufactured by PHISICAL ELECTRONICS was used. The measurement was performed under the condition that the acceleration voltage of the electron gun was 10 kV and the sample current was 500 nA. Further, the acceleration voltage of the Ar ion gun was set to 2 kV, and the sputtering rate was set to 8.2 nm / min.

  As shown in FIG. 2, the value of atomic percentage (at%) of Si gradually increases from the surface of the DLC film toward the test piece, and conversely, the value of atomic percentage of carbon (C) is the value of the DLC film. It gradually decreases from the surface toward the test piece. This indicates that the concentration of Si contained in the DLC film continuously changes so as to be high at the interface with the test piece and low at the surface.

FIG. 3 shows the measurement results of the DLC film formed by supplying C ₆ H ₆ gas and tetramethylsilane under different conditions. Thus, the change in Si concentration near the surface of the DLC film may be increased.

  FIG. 4 shows the results of measuring the crystal structure of carbon atoms for the obtained DLC film. The measurement was performed using an NRS-3200 microscopic laser Raman spectrophotometer manufactured by JASCO Corporation, the excitation wavelength was 532 nm, the laser power was 10 mW, the diffraction grating was 600 lines / mm, the objective lens was 20 times, and the slit was 0. .Times.1.times.6 mm, exposure time was 60 seconds, and integration was twice.

  As shown in FIG. 4A, on the surface of the DLC film, the peak area showing diamond bonds (SP3 bonds) is larger than the peak area showing graphite bonds (SP2 bonds). On the other hand, as shown in FIG. 5B, at the interface with the test piece, the area of the peak showing the SP2 bond is larger than the peak showing the SP3 bond.

  The area of each peak was determined by curve fitting (band decomposition), and the ratio of the obtained peak areas was determined to determine the abundance ratio of SP2 bond and SP3 bond. As a result, SP3 of SP2 bond was found at the interface with the test piece. The abundance ratio to the bond was 0.46, and the abundance ratio of the SP2 bond to the SP3 bond was 1.17 on the surface. That is, at the interface with the test piece having a high Si concentration, there are few diamond bonds and many graphite bonds compared to the surface. This suggests that the hardness of the DLC film is lower at the interface with the test piece than at the surface.

  Actually, when the hardness and elastic modulus (Young's modulus) of the DLC film were measured, the hardness was 26 GPa and the Young's modulus was 113 GPa at the interface with the test piece having a high Si concentration. On the low surface, the hardness was 29 GPa and the Young's modulus was 210 GPa.

  The hardness and Young's modulus were measured by a nanoindentation method using a 90-degree triangular pyramid diamond indenter equipped with a high sensitivity (0.0004 nm, 3 nN) sensor manufactured by Hysitron. For the measurement of the indentation state, a scanning probe microscope (SPM) manufactured by Shimadzu Corporation, which is a microscope capable of observing a three-dimensional shape at a high magnification by scanning the surface of the sample with a fine probe, was used. . The measurement conditions by nanoindentation were controlled by indenting the diamond indenter with an accuracy of 100 μN, and the mechanical properties such as hardness and elastic modulus were quantified from the analysis of the load-displacement curve. The indenter pressing time was set to 5 seconds, and the drawing time was set to 5 seconds for measurement.

  FIG. 5 shows the results of measuring the heat resistance of the test piece on which the obtained DLC film containing Si and the test piece on which a DLC film not containing Si as a comparative example was formed. The temperature of the test piece was raised to 500 ° C. or 600 ° C. in an electric furnace, held for 3 hours, cooled to room temperature, and the surface condition was observed with a Keyence VK-9500 pinhole confocal microscope. did.

  As shown in FIG. 5, the test piece on which the DLC film containing Si of this example is formed has no cracks at 500 ° C. and 600 ° C. On the other hand, the test piece on which the DLC film not containing Si of the comparative example formed a crack at both 500 ° C. and 600 ° C. From the above results, the DLC film containing Si of this example has high heat resistance, and the molds and mechanical parts including the DLC film containing Si have excellent smoothness, wear resistance, and heat resistance. Obviously.

  The heat-resistant diamond-like thin film according to the present invention, the machine part and mold including the same, and the manufacturing method thereof can realize a DLC film excellent in heat and wear resistance and a machine part or mold including the DLC film. In particular, it is useful as a machine part, a mold, a manufacturing method thereof, and the like that are used at least intermittently exposed to a temperature of 300 ° C. or higher.

It is the schematic which shows the ionization vapor deposition apparatus used for manufacture of the diamond-like thin film which concerns on one Example of this invention. It is a result of the Auger electron spectroscopy analysis which shows the change of the component in the depth direction of the diamond-like thin film which concerns on one Example of this invention. It is a result of the Auger electron spectroscopy analysis which shows the change of the component in the depth direction of the diamond-like thin film which concerns on the modification of one Example of this invention. (A) And (b) shows the measurement result of the abundance ratio of SP2 bond to SP3 bond in the DLC film of the diamond-like thin film according to one embodiment of the present invention, (a) is the Raman spectrum on the surface, (b ) Is the Raman spectrum at the interface with the stent body. It is a laser micrograph which shows the result of the heat resistance test of the diamond-like thin film which concerns on one Example of this invention.

Explanation of symbols

21 Plasma generator 22 Target

Claims (29)

Formed to cover the substrate,
Contains silicon,
The silicon concentration at the interface with the substrate is higher than the silicon concentration on the surface,
A heat-resistant diamond-like thin film characterized in that a change in silicon concentration between the interface with the substrate and the surface is continuous. A substrate;
A diamond-like thin film covering the substrate and containing silicon;
The diamond-like thin film is a mechanical part characterized in that the concentration of silicon on the surface is lower than that of the interface with the substrate, and the concentration of silicon is continuously changing.   The mechanical part according to claim 2, wherein the diamond-like thin film has an atomic percentage concentration of silicon of 50% or less in a portion where the silicon concentration is highest.   The mechanical part according to claim 3, wherein the diamond-like thin film has the highest concentration of silicon at the interface with the base material.   The mechanical part according to claim 3 or 4, wherein the diamond-like thin film has a silicon concentration of 90% or less of a silicon concentration in a portion where the silicon concentration is highest.   The mechanical component according to claim 2, wherein the diamond-like thin film has an elastic coefficient on a surface thereof larger than an elastic coefficient at an interface with the base material.   The mechanical component according to claim 6, wherein the diamond-like thin film has an elastic coefficient of 50 GPa or more and 400 GPa or less on a surface thereof.   The diamond-like thin film has graphite bonds and diamond bonds, and the abundance ratio of graphite bonds to diamond bonds on the surface of the diamond-like thin film is smaller than the abundance ratio of graphite bonds to diamond bonds at the interface with the substrate. The machine part according to claim 2, wherein   The machine part according to claim 2, wherein the base material has an arithmetic average surface roughness of 0.1 nm or more and 300 nm or less on a surface thereof. Preparing a substrate (a);
And (b) forming a diamond-like thin film containing silicon on the surface of the base material,
In the step (b), the diamond-like thin film is formed such that the concentration of silicon on the surface is lower than the interface with the substrate and the concentration of silicon continuously changes. Manufacturing method of machine parts.   The said diamond-like thin film is formed in the said process (b) so that the atomic percentage concentration of the silicon in the part with the highest silicon concentration may be 50% or less, The manufacturing of the machine component of Claim 10 characterized by the above-mentioned. Method.   12. The method of manufacturing a mechanical part according to claim 11, wherein in the step (b), the diamond-like thin film is formed so that the concentration of silicon is highest at the interface with the base material.   12. In the step (b), the diamond-like thin film is formed so that a silicon concentration on the surface thereof is 90% or less of a silicon concentration in a portion where the silicon concentration is highest. Or the manufacturing method of the machine component of 12.   The said diamond-like thin film is formed in the said process (b) so that it may become larger than the elastic modulus in the interface with the said base material in the surface, The mechanical component manufacture of Claim 10 characterized by the above-mentioned. Method.   In the step (b), the diamond-like thin film has a graphite bond and a diamond bond, and the ratio of the graphite bond to the diamond bond on the surface of the diamond-like thin film is such that the graphite-bonded diamond bond at the interface with the substrate. It forms so that it may become smaller than the ratio with respect to this. The manufacturing method of the machine components of Claim 10 characterized by the above-mentioned. Mold body,
A diamond-like thin film covering the mold body and containing silicon;
The diamond-like thin film is characterized in that the concentration of silicon on the surface is lower than the interface with the mold body, and the concentration of silicon is continuously changing.   The mold according to claim 16, wherein the diamond-like thin film has an atomic percentage concentration of silicon of 50% or less in a portion where the silicon concentration is highest.   The mold according to claim 17, wherein the diamond-like thin film has the highest silicon concentration at the interface with the mold body.   The mold according to claim 17 or 18, wherein the diamond-like thin film has a silicon concentration of 90% or less of a silicon concentration in a portion where the silicon concentration is highest.   The mold according to claim 16, wherein the diamond-like thin film has an elastic coefficient on a surface thereof larger than an elastic coefficient at an interface with the mold main body.   21. The mold according to claim 20, wherein the diamond-like thin film has an elastic coefficient of 50 GPa or more and 400 GPa or less on the surface thereof.   The diamond-like thin film has a graphite bond and a diamond bond, and the abundance ratio of the graphite bond to the diamond bond at the surface of the diamond-like thin film is greater than the abundance ratio of the graphite bond to the diamond bond at the interface with the mold body. The mold according to claim 16, which is small.   The mold according to claim 16, wherein the mold main body has an arithmetic average surface roughness of 0.1 nm or more and 300 nm or less on a surface thereof. Preparing a mold body (a);
Forming a diamond-like thin film containing silicon on the surface of the mold body (b),
In the step (b), the diamond-like thin film is formed such that the concentration of silicon on the surface is lower than the interface with the mold body and the concentration of silicon continuously changes. Mold manufacturing method.   25. The mold production according to claim 24, wherein, in the step (b), the diamond-like thin film is formed so that an atomic percentage concentration of silicon in a portion having the highest silicon concentration is 50% or less. Method.   12. The method of manufacturing a mold according to claim 11, wherein in the step (b), the diamond-like thin film is formed so that a concentration of silicon is highest at an interface with the mold body.   12. In the step (b), the diamond-like thin film is formed such that the concentration of silicon on the surface thereof is 90% or less of the concentration of silicon in the portion with the highest silicon concentration. Or the manufacturing method of the metal mold | die of 26.   25. The gold according to claim 24, wherein, in the step (b), the diamond-like thin film is formed such that an elastic coefficient on a surface thereof is larger than an elastic coefficient at an interface with the mold body. Mold manufacturing method.   In the step (b), the diamond-like thin film has a graphite bond and a diamond bond, and the abundance ratio of the graphite bond to the diamond bond on the surface of the diamond-like thin film is such that the graphite bond at the interface with the mold body. 25. The method for producing a mold according to claim 24, wherein the mold is formed so as to be smaller than the abundance ratio with respect to diamond bonds.